There is a liquid crystal display device which includes, as a backlight which irradiates a liquid crystal display panel with light from behind, a surface illuminant in which light sources such as LEDs (light emitting diodes) are provided. Such a backlight, which irradiates a liquid crystal display panel with light from behind, is called a direct type backlight.
Patent Literature 1 discloses a direct type backlight in which a plurality of LEDs are provided so as not to be in contact with each other. The respective plurality of LEDs emit light rays which are mixed to be uniform white light. The backlight includes (i) a base substrate, (ii) LEDs which are provided on the base substrate and emit blue light, red light, and green light, respectively, (iii) a diffusion plate which is provided above the LEDs, and (iv) lenses which are provided for the respective LEDs so as to cause emitted light to be directed toward the diffusion plate. Moreover, radiation angles of the respective lenses are adjusted so that the light rays emitted by the respective LEDs are mixed in a common area of the diffusion plate.